This standard specifies the classification, technical requirements, Encasement, marking and storage of torsional vibration measuring instruments (torsional vibration instruments) for internal combustion engine shafting. Apply to instruments for the measurement of physical quantities such as angular amplitude, Frequency, shaft segment torque or stress of internal combustion engine shafting. The standard covers digital, analog (including laser) torsional vibration instruments, torsional vibration stress measuring instruments and mechanical torsional vibration instruments. The torsional vibration instrument must have a mass certificate of conformity and can accurately measure the torsional response and Rotation speed information of the measured shafting, and must meet the requirements of Frequency range and Linear dispersion of amplitude and frequency characteristics.